GD problems

I recompiled my Apache webserver over the weekend to version 2.2.4 and PHP 5.2.1 to get the latest security updates and whatnot. The configure line that I used is the following:

./configure --build=i386-redhat-linux --host=i386-redhat-linux --target=i386-redhat-linux-gnu --with-apxs2=/usr/local/apache2/bin/apxs --with-pic --disable-rpath --with-bz2 --with-curl --with-exec-dir=/usr/bin --with-freetype-dir=/usr --with-png-dir=/usr --enable-gd-native-ttf --without-gdbm --with-gettext --with-gmp --with-iconv --with-openssl --without-pspell --with-expat-dir=/usr --with-zlib --with-layout=GNU --enable-exif --enable-ftp --enable-magic-quotes --enable-sockets --enable-sysvsem --enable-sysvshm --enable-sysvmsg --enable-track-vars --enable-trans-sid --enable-yp --enable-wddx --with-pear=/usr/share/pear --with-kerberos --enable-ucd-snmp-hack --enable-memory-limit --enable-shmop --enable-calendar --enable-dbx --enable-dio --with-mime-magic=/etc/httpd/conf/magic --without-sqlite --with-libxml-dir=/usr --with-xml --with-mysql --with-gd --without-odbc --with-xsl --with-tiff-dir=/usr/local --with-jpeg-dir=/usr --with-jpeg --with-png --with-tiff

Everything seemed to go well until I went to upload a JPEG image in Drupal. (PNG works correctly, it's only JPEGs that are causing problems.) The image module threw the error "Unable to create thumbnail image." After searching around here, I determined it was most likely a problem with GD lacking . However, based on the config line above, I can't figure out why JPEG support is not enabled.

Like I said, I'm pretty sure this isn't a problem with Drupal, but if anyone could help me out with this I'd appreciate it.